Parallel operated gas filled tube



Oct. 16, 1934. sw R 1,977,255

PARALLEL OPERATED GAS FILLED TUBE Filed March 17, 1933 Gas filled tube:

Gus filled INVENTOR Sunni :6

ATTORNEY Patented Got. 16, 1934 PATENT FFICE PARALLEL OPERATED GASFILLED TUBE Leland K. Swart, .Mountain Lakes, N. .L, assignor toAmerican Telephone and Telegraph Comp y, a corporation of ApplicationMarch 17,

8 Claims.

This invention relates to electrical circuits and systems. Moreparticularly, this invention relates to electrical circuits and systemsemploying gas filled tubes. Still more particularly, this inventionrelates to electrical circuits and systems employing gas filled tubesoperated in parallel relationship.

It is well known that a tube having two spaced electrodes which areenclosed within an envelope filled with a gaseous medium such as neon,argon, helium or krypton gas or a combination of these gases or acombination of these gases and mercury vapor or hydrogen gas or the likewill exhibit special characteristics when the voltage impressed acrossthe electrodes exceeds a predetermined value. 'When this predeterminedvalue of voltage is exceeded, the gas within the tube will becomeionized and a discharge will occur between the electrodes of the tube.This will result in a substantial drop in impedance within the tube, theimpedance before ionization being extremely high and almost infinite andafter ionization very low and almost negligible. It is I also well knownthat after discharge occurs between the electrodes of such a tube, thevoltage required to sustain the discharge between the electrodes will beof substantially lower value.

The voltage characteristics of twosuch tubes, although intended to beprecisely the same, will differ slightly due primarily to minutevariations in their dimensions. It will be found that the discharge gapsof thesetubes will be broken down at slightly different voltages. Whenthe voltage in a line to which two such tubes are connected in parallelrelationship exceeds that required to break down the gap of one of thesetubes, for instance,.the tube of slightly lower breakdown voltage, theimpedance across the latter tube will become greatly reduced. If thevoltage in the line tends to rise above that required to breakdown thegap of the second tube, the tube which has broken down will receivepractically all of the current transmitted by the line and this tubewill prevent the discharge gap of the second tube from being brokendown. It follows, therefore, that when two or more of such tubes areconnected in parallel relationship, immediately after the gap of one ofthe tubes has become broken down,

; it will be practically impossible to break down the gap of any of theother of the tubes without damage to the first mentioned tube.

. One of the objects of this invention is to provide an arrangement forinterconnecting two or more I: gas filled tubes in parallel relationshipso that New York 1933, Serial No. 661,411

the discharge gaps of all of these tubes may be simultaneously brokendown.

Another of the objects of this invention is to provide an arrangementincluding a plurality of impedances which may be connected in serieswith a plurality of gas filled tubes, one impedance being connected inseries with each tube, so that all of these tubes may becomesimultaneously discharged.

Another object of this invention is to connect a plurality of gas filledtubes in parallel relationship and simultaneously discharge the gaps ofall of said tubes so that each will carry a predeter mined portion ofthe total load intended to be carried by said tubes.

This invention will be better understood from the detailed descriptionhereinafter following when read in connection with the accompanyingdrawing in which Figure 1 shows one arrangement for carrying out theprinciples of this invention; Fig. 2 shows another arrangement which isintended to be operated from both halves ofeach impressed alternatingcycle; and Figs. 3 and 4 are modifications of Figs. 1 and 2,respectively, these modifications including apparatus for resetting allor" the tubes to their normal conditions immediately after they havebecome operated.

Referring to Fig. l of the drawing, the reference character D designatesa circuit transmitting voltages which may vary over a wide range ofvalues. The circuit D is connected to an impedance Z0 and the voltageacross this impedance will correspond to that impressed thereon by thecircuit D.

The reference characters N1 and N2 represent two gas filled tubes eachof which includes two cathodes designated K1 and K2 and an anodedesignated A. Each of these tubes is filled with a gaseous medium of thecomposition described hereinabove.

The cathode K1 of the tube N1 is connected to the upper terminal of theimpedance Z0 through an impedance Z1. The cathode K1 of the tube N2 isconnected to the upper terminal of the impedance Z0 through an impedanceZ2. The impedances Z1 and Z2 are preferably substantially equal and,moreover, their magnitudes are very large when compared to theimpedances between the cathodes K1 and K2 of either of the tubes N1 orN2.

An operating relay designated R includes two windings W1 and W2, theupper terminal of winding W1 being connected to the anode A of the tubeN1 and the upper terminal of the winding W2 being connected to the anodeA of the tube N2.

The lower terminals of the windings W1 and W2 are connected to eachother and the conductor common to them is connected to the lowerterminal of the impedance Z0 through a source of potential designated Bwhich is preferably a source of direct current potential but which may,if desired, be one of alternating potential, as will be describedhereinafter. 7

The'cathode K2 of the tube N1 and the cathode K2 of the tube N2 areconnected to eachother and the conductor common thereto is connected tothe lower terminal of the impedance Z0 through a source of potentialdesignated C." This source C may be either a direct current potential oran alternating current potential and it is employed primarily forbiasing the cathodes K1 of both tubes N1 and N2 to apredeterminedpotential with respect to the cathodes K2 of these tubes.

When a voltage is impressed by the circuit D upon the impedance Z0, thatvoltage will also be impressed through the impedance Z1 between thecathodes K1 and K2 of the tube N1. The same voltage will also beimpressed through the impedance Z2 between the cathodes K1 and K2 of thetubeNz. If the voltage impressed between the cathodes K1 and K2 ofthetube N1 is sufficient not only to ionize the gas within that tube butalso to break down the gap between these electrodes, then this samevoltage will generally be sufficient to-ionize the gas within the tubeN2 and break down the gap between the cathodes K1 and K2 or the lattertube. Inasmuch as both tubes have substantially the same breakdownvoltages between their cathodes K1 and K2, and because the impedances Z1and Z2 in series with the cathodes K1 and K2 of the tubes N1 and-N2,respectively, have magnitudes substantially higher than the impedancesbetween these cathodes, the gaps between these cathodes will bedischarged virtually, simultaneously. The impedance between the cathodesK1 and K2 of the tube N1 will represent a small portion of the totalimpedance in the circuit in series with these cathodes and theimpedancebetween the similar cathodes K1 and K2 of the tube N2 willrepresenta correspondingly small portion of the total impedance in the:cir-

cuit in series with the latter cathodes. By vir tue of this condition,it will almost invariably happen that the discharge gaps of both tubeswill be simultaneously broken-down if only the voltage impressed betweenthe cathodes' of these tubes is suiiicient to icnize the gas within thetube having the'higher breakdown voltage.

It will be noted that the winding W1 of the relay R- is in a circuit inseries with the anode A and the cathode K2 of the tube N1 and that theWinding W2 of the relay R is in a circuit in series with the anode A andthe cathode K2 of the tube N2, both circuits being in parallelrelationship, the elements in common with both parallel circuitsincluding the sources 13 and (has shown. Inasmuch as both tubes N1 andN2 have substantially the same characteristics, there will be,substantiallyequal discharges between the cathode K and the anode A' ofboth tubes N1 and: N2 after the gaps between cathodes K1 and Kz of bothtubes have been-broken down. Inasmuch as the tubes N1 and N2 are ofsimilar construction, substantially equal currents will flow from thesource of'therelay wh'ichis employed for closing a circult controlled bythis armature. 1

One' of the features ofthis' invention" lies in the employment of awinding or an impedance in series with the anode of each of the tubes N1and N2. By including substantially high impedances in the windings W1and W2, 1. e., impedances which are much greater than the impedancesbetween the anode A and cathode K2 of the corresponding tube,substantially equal currentswill be transmitted through the circuitsformed bythe anode A and the cathode K2 of these tubes. In other words,the anode or output circuits of both tubes 'will carry substantiallyequal portions of the total current flowing from source B through thetwo windings-of the relay R.

Fig. 2 shows an arrangement for operating with considerable efficiencyduring both halves of each cycle of alternating potential transmitted bythe circuit D. Fig. 2 includes four gas filled tubes N1, N2, N3 and N4,two of which are caused to operate from the one-half cycle of an appliedalternating current cycle and the other two of which will be caused tooperate from the other half of the alternating current cycle. N

The source D is connected inseries' with impedances Z11 and Z12. Theimpedance Z11 is connected to the cathodes K1 and K2 of the-tube N1through the impedance Z1 and the source of po tential C. The impedanceZ12 is connected to the cathodes K1 and Kz-of the tube N2 through theimpedance Z2 and the source or potential C. The impedance Z 1 isconnected to the-cathodes K1: and K2 of the tube N2 through theimpedance Z3 andthe source of potential C. The impedance Z12isconnectedto the cathodes K1 and K2 of the tube N4 through theimpedance Z4 and the source of potential C. 1 It will be evident thatthe source of potential C is employedto, bias one of the cathodes ofeach of the tubes N1, N2, N3 and N to a predetermined potential withrespect to the other'cathode of each of these tubes. It will also beevident that the impedances Z1, Z2, Z3 and Z; are connected in serieswith the two cathodesof each corresponding-tube so thatthe gaps betweenthe cathodes of all of the tubes will be practically simultaneouslybroken down immediately after the circuit D transmits a sufficientlyhigh direct or alternating voltage.

The relay R includes four, windings W1, W W3 and W4 and one terminal ofeach ,of these windings is connected to the anode A of the correspondingtube N1, N2, N3 or N4, as shown. The other terminals-of these windingsare connected to each other and their common conductor is connectedthroughthe source ofpotential B to the. terminal common to theimpedances Z11 andZ12L' V I v During the first half of each alternatingcurrent cycle, a voltage will be impressed acrcssthe impedances Z1 andZ12 which will be in only one direction and this voltage, if largeenough, will break down the gaps between the cathodes K1 and'Kz of twoof the tubes which will at that time'b'e operated in parallelrelationship. during the first half of each alternating current cyclethe voltage impressed across the impedance Z12 may, for instance,be'poled so as to cause the gaps between the cathodes K1 and K2 0 thetubes N1 and Nzflto be simultaneously broken down. During'the succeedingha f of each alter nating current cycle, the voltage impressed acrossthe impedance Z12 will be so poled as to cause the discharge gapsbetween the cathodes I-i1and K2 of the tubes N2 and N4,- which are alsooperated in parallel relationship, to become simultaneously broken down.v For'one half of an appliedalternating' current in windings W1 and W2.that the armature of the'relay R will be caused cycle, the windings W11and We will be supplied to operate from the first half of an applieda1terhating current cycle impressed upon the circuit D, provided thevoltage of the alternating current issufficien-t to bring about abreakdown of the gaps of any of the various tubes.

Fig. Bellows an arrangement f or returning the gas filled tubes to theiroriginal condition-after their gaps have been broken down by thetransmission of a voltage exceeding a predetermined value. Withoutsomeform of arrangement for resetting the gas filled tubes to their initialcondition in which the gaps arefree to become again discharged whenimpressed withfurther voltages exceeding the predetermined value, itwill be impossible to continuously discriminate between the applicationof voltage or the a sence of voltage applied to the input circuit. 1 1

Fig. 3 shows an arrangement somewhat similar to theone shown in Fig. 1.Fig. 3 includes, however, a vibrating relay, the armature of which iscapableof vibrating at an extremely high speed and it also includes acircuit for resetting the gas filled tubes to their initial conditionimmediately ter their gaps have become discharged by applied voltage. VV

,The vibrating relay is designated R11 and it has .two windings W11and.-W1'2. The winding W11-is connected between the anode A of the gasfilled tube N1 and thecathode K2 of the tube N1 through a circuit whichincludes impedance Z11, which may be a resistance of low magnitude, anda condenser C which is of large capacity.- The other winding W12 of thevibrating relay R11 is connected between the anode A of the; tube N andthe cathode K2 of that tube through the same circuit of impedance Z 1and condenser C. The sources B and C are preferably direct currentsources, such as storage batteries,;and. they are connectedin seriesrelationship so that their voltage effects are additive, the seriescircuit including an. impedance Z12, the winding of an operating relayR, the impedance Zn and the condenser C. It will be noted that thearmature and con} tact of the vibratory relay R 1. are bridged acrossthe series elements of impedance Z11 and capacity C. f

It will be apparent thatv when thecircu'it D transmits a voltage above apredetermined value, the gas within the tubes N1 and N will becomeionized, the gaps between the cathodes K and K2 of these tubeswillbecome broken down and current will flow simultaneously between theanodes A'and the cathodes Kz of both tubes N1 and N2. The currentemanating frorn sou rces B and C will fiow through impedance Z theoperating winding oftherelay 'R and it will divide substantially equallybetween the windings W11 and W12, respectively, The flow of currentthrough the circuit just described willfattract the armature ofthe-operating relay R, c1osing the circuit controlled by this armature.

After the vibrating relay R11 has become opercited, as willbe thecaseimmediately after a high voltage has become impressed'upon the line D,

the armature of the vibrating relay willclose a circuit which willcompletely shunt out thecurrent flowing through the windings W11 and W12of the vibrating relay and'between the anodes A and cathodes K2 ofthetubes N1 and N2, respec- 1i,

tively. This will cause a substantial increase in the flow of currentthrough the winding of the operating relay R, current then flowing frombatteries C and B through the impedance Z12, the operating winding ofthe relay Rand the armature and contact of the vibrating relay R11. Atthe same time, any charge upon the condenser C will tend to becomedissipated through the impadance Z11. Furthermore, the flow of currentthrough the'armature and contact of the vibratirig relay R11 will reducethe current tending to,

flow through the windings Wuand W12 and between the anodes A and thecathodes K2 of the tubes N1 and N2, respectively, to a practicallynegligible value and thereby transform the gas within these tubes to itsinitial de-ionized condition, provided that the voltage transmitted bythe circuit D remains insufiicient to cause ionization between thecathodes K1 and K2 of these tubes. After the current through theparallel circuit just described has become reduced to a negligiblevalue, the magneto-motiveforce of the windings of the vibrating relayR11 will be insuflicient to hold the armature closed against itscontact, and consequently, the circuit formed by this armature and itscontact will become opened. Hence current may thereafter flow frombatteries C and B through impedance Z12. the operating winding of therelay R and through the parallel paths formed by the windings W11 andW12 of-the vibrating relay Rnand the corre sponding paths formed bytheanodes A and cathodes K2 of the tubes N1 and N2, respectively, only ifthe voltage transmitted bythe circuit D is sufficiently great tocontinue the ionization of the gas within the tubes Ni-and N2 and breakdown thegaps between the cathodes of these tubes. So it will be-seenthat as long as a sruiiciently high voltage is transmitted by thecircuit D, the gas within the tubes N1 and N2 will become ionized andremain ionized and the impedance or all of the gaps of both tubeswill-be reduced toua practically negligible value and it will be notedthat the relay R11, which is of the vibrating type, will cause thecontinuous opening and closing of the contact'of that relay by itsarmature at a high speed. lvloreover, the vibration of the armature ofrelay R11 will cease almost instantly after the voltage transmitted bythe circuit D becomes reduced below that required to produce ionizationwithin the tubes N1 and N2.

Immediately upon the openin of the contact of the vibrating relay R11,the winding of the operating relay R will produce a. substantial voltagekick which may of itself produce ionination of the gas within tubes N1and N2, if this voltage is allowed to become transmitted through thewinding W11 and W12 0:" the vibrating relay R11. In order to reducethispossibility of deionization of these tubes in the absence of asufficiently high voltage in the circuit D, the condenser C andimpedance Z1'1 of small resistance areconnected in series-with theoperating winding of the relay B, thereby causing the voltage producedby the very high inductance of the operating winding of the relay l-t'to be shunted through the impedance Z11 and condenser C. In fact,'thecondenserC becomes charged by the inductive kick of the winding of theoperating relay R. The armature of the operating relay R are connectedin series with the anodes A of,

tubes N1, N2, N3 and N4, respectively, the operating winding of therelayR, the battery B, the battery 0, and the cathodes K2 of the tubes N1,N2, N3 and N4, respectively, as shown. It will be Mnoted'that'thearmature and contact of the vibrating relayRn are connected in shuntacross the circuit which includes the impedance Zn and the condenser C.In this arrangement, the vibrating relay R11 will produce a continuousvibration of its armature as long as the voltage transmitted by thecircuitD is sufficiently great to bring about the breaking of the gapsbetween cathodes K1 and K2 of the various tubes N1, N2, N3 and N4. Itwill be further noted that the armature of the operating relay R willclose its contact and that this contact will remain closed as long asthe relay R11 contmuesto vibrate its armature. The circuit shown willbring about the de-ionization of each of the various tubes almostimmediately after the voltage transmitted by the circuit D becomesinsufiicient to ionize the gas within any one of the various tubes andproduce a discharge between its electrodes.

It will be understood that the tubes designated N1, N2, N3 and N4 may beeither of the hot cathode gaseous type or cold cathode gaseousv type,both of which are well known.

It will be further understood that the various tubes may have electrodesso spaced and their gaseouspressures so adjusted that current will notbedivided equallybetween the output electrodes of these tubes; thecurrents transmitted through the output circuits of these tubes may, ifdesired, be divided therebetween in any other predeterminedrelationship, all of which is within thescope of this invention. a

It will also be understood that the impedances designated Z1, Z2, Z3 andZ4 may be any typeof impedance, that is, inductance or capacitance, andneed notnecessarily be simple resistance.

It will be further understood that the operating relay may be replacedby any form of translating device or circuit or, if desired, the relaymay be employed to control any well-known translating device or circuit.

And it will be further understood that the source designated C may be ofthe direct current type, the alternating current type or of theinterrupted direct current type. In the arrangements shown in Figs. land2, the source designated B may be of the alternating current'type ,or ofthe interrupted direct current type. I

While this invention has been shown and described in one particularembodiment merely for the purpose ofv illustration, it willbe understoodthat the general principles'of this invention may be applied to otherand widely varied organizations without departing from the spirit of theinvention and the scope-of the appended claims.

What is claimed is: 7 w v 1. The combination of two gas filled tubeseach having three electrodes, two impedances, each of 'said-irnpedancesbeing connected in series with two of the electrodes of one of the gasfilled tubes,

means for impressing voltages through said impedancesupon the twoelectrodes of both tubes which are in serieswith said impedances, andmeans interconnected. between the third electrode of each tube andeither of the other elec- 1' voltage exceeding a predetermined valueimpressed upon two of the electrodes of both tubes to simultaneouslyionize the gas within both tubes and substantially reduce the impedancebetween all of the gaps within both tubes; and means connected betweenthe third electrodes of both tubes and one of' the other electrodes ofboth tubes which becomes responsive to the change in the'impedance ofthe gaps of both tubes.

3. The combination of a plurality of gas filled tubes each having aninput circuit terminating in electrodes within each tubeand forming agap and an output circuit also terminating in electrodes within eachtube and forming'a'nother gap, means forsimultaneously breaking the gapsbetween the input circuit electrodes of all of said tubes, a-relayhaving a plurality of windings each of which is connectedto one oftheoutput circuit electrodes of each of .said tubes,'the output circuitelectrodes of all of said tubes being arranged in parallelrelationship,and means for vibrating the armature of said relay continuously as longas the gaps terminating the input circuit electrodes of said tubes arebroken down;

I 4.. The combination of a'plurality of gas filled tubes each having atleast two gaps between its electrodes, means responsive to a voltageexceed ing a predetermined value for simultaneously breaking one of. thegaps of each of said tubes, and a translating circuit connected incommon to one of the remaining gaps of each of said tubes, ill

the latter gaps being arranged inparallel relationship. 1 a

5. The combination of a plurality of 'gas'filled tubes each havingelectrodes forming a firstga'p and a second gap, the first gap'ofone-of'said tubes being connected'in parallel relationship with thefirst gap of each of the'other of said tubes, means responsive toa-voltage exceeding'a predetermined value for simultaneously breakingall of said first gaps, a relay having a plurality of windingseach ofwhich is connected in parallel relationship with the second gap'o'f oneof said tubes, and a circuit controlled by the armature of said relay. r

6. The combination of a plurality of gas filled tubes each having aplurality of electrodes forming gaps, meansresponsive to a voltageexceeding a "predetermined value for simultaneously breaking the gapsof, all ofrsaid'tubes, a relay having a fast vibrating armature, andmeans responsive to the breakingof the gapsof said tubes for vibratingthe armature of said relay and for maintaining the armature incontinuous vibrationas long as said'gaps are broken.

7. The combination of two gasfilled tubes each V having'a plurality ofelectrodes forminggaps, means. responsive to a voltage exceeding apredetermined value for simultaneously breaking the gaps of. all of saidtubes, a translating circuit, means interposed between the translatingcircuit and the various tubes for operating the translating circuit whenthe gaps of the tubes are brokne down,.and means for restoring.the'tubes to their initialcondition after the voltagewhich ting voltagesthrough said impedances to the electrodes in series with said impedancesand for simultaneously breaking down the gaps between said electrodeswhen the transmitted voltage exceeds a predetermined value, and atranslating circuit connected in common with the third electrode and oneof the other electrodes of each of said tubes.

LELAND K. SWART.

